I agree with you STEEVE - those inserts look to be what we call a 'bodge' fix, here in the UK. (You could fabricate something similar from chewing gum - it sets semi-hard eventually !).
I hope you get more time to sort the problem now the weekend is here.
If I were just up the road from you (which I aint) I would bring round 2 things:
A set of BKL rings which are near as dammit guaranteed to be correct (by all who use them), preferably the double strap variety (but I only have the single type unmounted right now/here -
its a PCP not .50 cannon, they would be equally OK).
A simple uncomplicated scope like an old Simmons WTC.
I would suggest trying in that order on a Cost / Benefit way of thinking (mounts are cheaper than scopes).
That's even though I suspect the scope you have. But my big heavy hand of guidance

would be to try/test only ONE thing at a time.
Well, that's all just guidance, of course - keep us posted & we are all
on your side here !